                  (fun rate num-outs args spec))]
 
     (if (string? result)
-      (throw (Exception. (str "Error in checker for ugen " (:name spec) ". " result)))
+      (throw (Exception. (str "Error in checker for ugen " (overtone-ugen-name (:name spec)) ". " result)))
       ugen)))
 
 (defn- check-arg-rates [spec ugen]

                 auto-rater
                 nil-arg-checker
                 rate-checker
                 bespoke-checker)))))

(defn- with-fn-names
  "Generates all the function names for this ugen and adds a :fn-names map

        checker-fn      (if (contains? spec :check)
                          (:check spec)
                          placebo-ugen-checker-fn)
        bespoke-checker (partial with-ugen-checker-fn spec checker-fn)
        sanity-checker  (partial with-ugen-checker-fn spec sanity-checker-fn)]

    (assoc spec :init

